You already have the best fat-burning equipment: your feet. The secret is knowing how to use them. Whether you're a novice walker or a regular who's hit a plateau, we'll help you whittle down in four weeks, just in time for beach season.

Our program is specifically designed to bump your body into a higher calorie- and fat-burning zone, so those flabby trouble spots will get firm in no time. You'll do four 30-minute walking workouts a week--on Tuesday, Thursday, Saturday, and Sunday. And on each day, you'll work different muscles. The step-by-step details are charted out for you in "Our Fat-Blasting Walking Plan", but here's a quick breakdown of your activities for each day--and how they'll make the weight-loss difference.

Tuesdays Walk normally...then have a speed burst for one to two minutes. Go as fast as your feet will carry you, but try to maintain good form (see "Burn Fat Faster"). This extra "fast lane" push makes your metabolism work overtime, so you may burn more calories post-exercise.

Thursdays March up inclines. If there are hills nearby, choose those that are about a block long. On treadmills, simply increase the incline to about 4 percent. No hills, no treadmill? Get the same muscle boost by walking up a long flight of stairs for 60 seconds. You'll see results fast: Tufts University researchers reported that older adults who added lean muscle tissue through resistance exercises boosted their resting metabolism rate by about 7 percent. That means they burned extra calories, even when they were just sitting around.

Saturdays Take a brisk and steady walk to build stamina and strength. Find a pace that's quick enough for you to feel a burn, but not so tough that you can't sustain it for at least 20 minutes.

Sundays This is your day of rest. Translated: You can walk as slow or fast as you like. Just make sure you get out there and hit the pavement.

Ready to march out the door? Before you do, put on the comfiest sweat-wicking gear (see our GHRI-tested picks). And if you can, find a workout buddy--studies show that you'll help each other stay committed.